DETAILED ACTION Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 07/08/2026 has been entered.
Response to Amendment
The Amendment filed 07/08/2026 has been entered.
Response to Arguments
Applicant's arguments filed 07/08/2026 have been fully considered but they are not persuasive. The newly added limitations in claims 1 and 11 are well known in the art of Doherty power amplifiers and how they operate (see rejection below), even if the limitations are not explicitly mentioned in the primary reference. The purpose of referencing different prior arts is to show common knowledge in the art.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 21-22 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 21, it states that the first state is less than threshold and second state is greater than threshold. However, par. 129 of the specification states the opposite; it says that a first state is when the output power is greater than or equal to a threshold value and the second state is when the output power is less than the threshold value. This discrepancy makes the claim unclear and indefinite. Applicant also states in their remarks that support for this new claim can be found in par. 96 of the specification, however, examiner was unable to understand what exactly from this paragraph helped support the limitations in claim 21, as this paragraph talks about phase differences, which the claim does not mention. Appropriate correction is required. Dependent claim 22 inherits this rejection.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1-9 and 11-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over US
20230198469 by Ladhani et al.
Regarding claim 1, Ladhani teaches a Doherty power amplifier in wireless communication system, comprising:
a first stage (Fig. 1 #110) including a first power amplifier (Fig. 1 #112) and a second power amplifier (Fig. 1 #114);
a second stage (Fig. 1 #120) including a third power amplifier (Fig. 1 #122) and a fourth power amplifier (Fig. 1 #124);
a coupler (Fig. 1 #104; Par. 18) between the first stage (#110) and the second stage (#120); and
a load impedance (Par. 21, 26) connected to the second stage (#120),
and wherein the Doherty power amplifier is configured so that a phase difference between an output current of the third power amplifier and an output current of the fourth power amplifier is changed in accordance with a magnitude of a signal input to the first stage, based on the bias of the first power amplifier being different from the bias of the second power amplifier and the bias of the third power amplifier corresponding to the bias of the fourth power amplifier, and wherein an impedance from the third power amplifier to the load impedance is modulated in accordance with the changed phase difference (It is common knowledge in the art that impedance will change based on the magnitude of the input signal, as shown in par. 9 of US 20150155838 by Embar et al. It is also common knowledge in the art that a phase difference between the main and peaking amplifier will change as the peaking amplifier is turned on. Initially when the peaking amplifier acts as an open circuit, the phase difference between the main and peaking amplifier is 90 degrees. As the input changes and power increases, the peaking amplifier turns on and the phase difference decreases until the two amplifiers are in phase with one another. As for the load impedance, initially when the peaking amplifier is off, the impedance is double the load impedance, but as the peaking amplifier is turned on and the phase difference decreases, the impedance also decreases).
Ladhani doesn't explicitly state the bias levels of the different amplifiers, however, different biasing levels are well known to a person having ordinary skill in the art. Teaching reference Lyalin has a Doherty amplifier system with a driver and output stage wherein a bias of the first power amplifier (Fig. 1 #116) is different (Abstract; Col. 2 lines 1-15) from a bias of the second power amplifier (Fig. 1 #136), and wherein a bias of the third power amplifier (Fig. 1 #120) corresponds (Abstract; Col. 2 lines 1-15) to a bias of the fourth power amplifier (Fig. 1 #140).Regarding claim 2, Ladhani (and Lyalin) teach the Doherty power amplifier of claim 1, wherein the first power amplifier comprises a power amplifier in which a bias is class-A or class-AB,
wherein the second power amplifier comprises a power amplifier in which a bias is class-B or class-C, and
wherein the third power amplifier comprises a power amplifier in which a bias is class-A, class-AB, or class-B. While Ladhani doesn't specify the class types of its amplifiers, biasing amplifiers in different classes is very well known to people having ordinary skill in the art as taught in Lyalin (Col. 6 lines 40-54).
Regarding claim 3, Ladhani teaches the Doherty power amplifier of claim 1, wherein the coupler (Fig. 1 #104) includes a first port connected to an output end of the first power amplifier (#112), a second port connected to an output end of the second power amplifier (#114), a third port connected to an input end of the third power amplifier (#122), and a fourth port connected to an input end of the fourth power amplifier (#124).
While Ladhani's circuit has a three port coupler, this is due to the fact that the outputs of both driver amplifiers are combined into a single input for the coupler. Four port couplers are very well known in the art, as shown in Fig. 1-3b, 20, 21 of US 20040189381 by Louis, and it would have been easy to substitute a four port coupler into Ladhani's circuit and have the individual outputs feed into the coupler rather than combine.
Regarding claim 4, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 1, wherein the coupler comprises at least one of a coupled line coupler, a lange coupler, a hybrid coupler, or a ring hybrid coupler (Par. 18).
Regarding claim 5, Ladhani teaches the Doherty power amplifier of claim 1, and while a transmission line is not used to connect the coupler to the third amplifier, using transmission lines to provide phase delay is very well known in the art of Doherty amplifiers, as shown in fig. 21 #282 of US 20040189381 by Louis. Where the transmission line is implemented is simply a matter of design engineering based on where a phase delay is needed. Transmission lines can also help with impedance matching between stages and would be easy to incorporate into the teachings of Ladhani.
Regarding claim 6, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 1, wherein the Doherty power amplifier further comprises a combiner (Fig. 1 # 130; Par. 16), wherein the combiner (#130) is connected to an output end of the third power amplifier (Fig. 1 #122), an output end of the fourth power amplifier (Fig. 1 #124), and the load impedance (Par. 21, 26).
Regarding claim 7, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 6, wherein the combiner comprises at least one of:
a lumped element, a lumped element and a transmission line, 10 a transmission line, or a lumped element and a transformer (Par. 22).
Regarding claim 8, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 1, wherein a magnitude of a first signal input to an input end of the third power amplifier corresponds to a magnitude of a second signal input to an input end of the fourth power amplifier (Par. 18).
Regarding claim 9, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 1, wherein the Doherty power amplifier further comprises a power splitter (Fig. 1; Fig. 2; see annotated drawing),
wherein the power splitter is connected to an input end of the first power amplifier (Fig. 2 #202) and an input end of the second power amplifier (Fig. 2 #204).
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Regarding claim 11, Lyalin teaches an electronic device in wireless communication system, comprising:
at least one processor (very well known in the art that electronic and amplifier circuits can have processors);
a plurality of antenna elements (Par. 21),
wherein the Doherty power amplifier comprises:
a first stage (Fig. 1 #110) including a first power amplifier (Fig. 1 #112) and a second power amplifier (Fig. 1 #114);
a second stage (Fig. 1 #120) including a third power amplifier (Fig. 1 #122) and a fourth power amplifier (Fig. 1 #124);
a coupler (Fig. 1 #104; Par. 18) between the first stage (#110) and the second stage (#120); and
a load impedance (Par. 21, 26) connected to the second stage (#120),
and wherein the Doherty power amplifier is configured so that a phase difference between an output current of the third power amplifier and an output current of the fourth power amplifier is changed in accordance with a magnitude of a signal input to the first stage, based on the bias of the first power amplifier being different from the bias of the second power amplifier and the bias of the third power amplifier corresponding to the bias of the fourth power amplifier, and wherein an impedance from the third power amplifier to the load impedance is modulated in accordance with the changed phase difference (It is common knowledge in the art that impedance will change based on the magnitude of the input signal, as shown in par. 9 of US 20150155838 by Embar et al. It is also common knowledge in the art that a phase difference between the main and peaking amplifier will change as the peaking amplifier is turned on. Initially when the peaking amplifier acts as an open circuit, the phase difference between the main and peaking amplifier is 90 degrees. As the input changes and power increases, the peaking amplifier turns on and the phase difference decreases until the two amplifiers are in phase with one another. As for the load impedance, initially when the peaking amplifier is off, the impedance is double the load impedance, but as the peaking amplifier is turned on and the phase difference decreases, the impedance also decreases).Ladhani doesn't explicitly state the bias levels of the different amplifiers, however, different biasing levels are well known to a person having ordinary skill in the art. Teaching reference Lyalin teaches a Doherty amplifier system with a driver and output stage wherein a bias of the first power amplifier (Fig. 1 #116) is different (Abstract; Col. 2 lines 1-15) from a bias of the second power amplifier (Fig. 1 #136), and wherein a bias of the third power amplifier (Fig. 1 #120) corresponds (Abstract; Col. 2 lines 1-15) to a bias of the fourth power amplifier (Fig. 1 #140).
Ladhani also doesn't teach a plurality of radio frequency (RF) chains connected to the at least one processor and that the plurality of antennas (Ladhani Par. 21) are connected to the plurality of RF chains. However, this is very well known to those having ordinary skill in the art as shown in Fig. 16 of Lyalin and Col. 8 lines 53-59. The plurality of devices can facilitate multi-band operation and it would be easy to configure the Doherty amplifier circuit of Ladhani in this way.
Regarding claim 12, Ladhani (and Lyalin) teach the Doherty power amplifier of claim 11, wherein the first power amplifier comprises a power amplifier in which a bias is class-A or class-AB,
wherein the second power amplifier comprises a power amplifier in which a bias is class-B or class-C, and
wherein the third power amplifier comprises a power amplifier in which a bias is class-A, class-AB, or class-B. While Ladhani doesn't specify the class types of its amplifiers, biasing amplifiers in different classes is very well known to people having ordinary skill in the art as taught in Lyalin (Col. 6 lines 40-54).
Regarding claim 13, Ladhani teaches the Doherty power amplifier of one claim 11, wherein the coupler (Fig. 1 #104) includes a first port connected to an output end of the first power amplifier, a second port connected to an output end of the second power amplifier, a third port connected to an input end of the third power amplifier, and a fourth port connected to an input end of the fourth power amplifier.
While Ladhani’s circuit has a three port coupler, this is due to the fact that the outputs of both driver amplifiers are combined into a single input for the coupler. Four port couplers are very well known in the art, as shown in Fig. 1-3b, 20, 21 of US 20040189381 by Louis, and it would have been easy to substitute a four port coupler into Ladhani’s circuit and have the individual outputs feed into the coupler rather than combine.
Regarding claim 14, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 1, wherein the coupler comprises at least one of a coupled line coupler, a lange coupler, a hybrid coupler, or a ring hybrid coupler (Par. 18).
Regarding claim 15, Ladhani teaches the Doherty power amplifier of claim 11, and while a transmission line is not used to connect the coupler to the third amplifier, using transmission lines to provide phase delay is very well known in the art of Doherty amplifiers, as shown in fig. 21 #282 of US 20040189381 by Louis. Where the transmission line is implemented is simply a matter of design engineering based on where a phase delay is needed. Transmission lines can also help with impedance matching between stages and would be easy to incorporate into the teachings of Ladhani.
Regarding claim 16, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 1, wherein the Doherty power amplifier further comprises a combiner (Fig. 1 130; Par. 16), wherein the combiner (#130) is connected to an output end of the third power amplifier (Fig. 1 #122), an output end of the fourth power amplifier (Fig. 1 #124), and the load impedance (Par. 21, 26).
Regarding claim 17, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 6, wherein the combiner comprises at least one of:
a lumped element, a lumped element and a transmission line, 10 a transmission line, or a lumped element and a transformer (Par. 22).
Regarding claim 18, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 1, wherein a magnitude of a first signal input to an input end of the third power amplifier corresponds to a magnitude of a second signal input to an input end of the fourth power amplifier (Par. 18).
Regarding claim 19, Ladhani (with Lyalin) teaches the Doherty power amplifier of claim 1, wherein the Doherty power amplifier further comprises a power splitter (Fig. 1; Fig. 2; see annotated drawing),
wherein the power splitter is connected to an input end of the first power amplifier (Fig. 2 #202) and an input end of the second power amplifier (Fig. 2 #204).
Regarding claim 21, it is well known in the art that the way Doherty amplifiers operate is by turning on the peaking amplifier once a certain threshold value is crossed and turning it off below said threshold value, as shown in par. 15 of US 20220416725 by van der Heijden et al.
Allowable Subject Matter
Claim 22 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
Conclusion
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/NAREH SHAMIRYAN/Examiner, Art Unit 2843
/ANDREA LINDGREN BALTZELL/Supervisory Patent Examiner, Art Unit 2843
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